Oil-switch.



PATENTED DEC. 3, 1907.

E. M. HEWLETT.

OIL SWITCH.

.APPLIOATION FILED JULY30,1904.

3SHEETS-SHEET 1.

Witpg 338 s Ipventor E dward MHewlett n1: Iva-vials PETERS 50., wsmuamu. c.

No 872,513. PATENTED DEC. 3, 1907. E. HEWLETT. OIL SWITCH.

APPLICATION FILED JULY 30. 1904.

3 SHEETS-BHEET 2.

fizi'gw I By EGWaJdMHQWltL Am orrzey PATENTED DEC. 3, 1907.

E. M." HEWLETT.

OIL SWITCH.

APPLICATION FILED JULY30,1904.

-3 SHEETS-SHEET 3.

7 hventor I EdwardMHewlett ww- Witnesses 22 1 .Attomey Ih'i NORRISPETERS co., WASHINGTON, n. c

UNITED STATES PATENT OFFICE.

EDWARD 3'1. HEWLETT, OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

OIL-SWITCH.

Specification of Letters Patent.

Patented Dec. 3, 1907.

Application filed il; 30, 1904. Serial No. 218,908.

To all whom it may concern:

Be it known that I, EDWARD M. HEWLETT, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Oil-Switches, of whichthe following is a specification.

The present invention relates to double throw switches of the typeemployed in starting alternating current motors, or in othercircumstances where a definite sequence of circuit connections isrequired.

It is well known that in starting alternating current motors by means ofa compensator it is necessary to first connect the motor terminals tothe compensator through a number of its coils so as to give the motorthe proper starting voltage, and subsequently when the motor has speededup to connect its terminals directly to the supply line. Under suchcircumstances a double throw switch may be employed to make the necessary connections.

The principal object of the present invention is to provide a novelswitch organization which may be easily manipulated to make the circuitconnections in the order desired and which will assist in preventing themaking of the connections in the wrong order.

To this end, I employ a restraining means which, when allowed tooperate, will permit the switch to be thrown from its starting to itsrunning position through its intermediate or open position but will stopthe switch in its open position whenever thrown from the runningposition.

My invention also comprises in combination with an electrically-operatedtrip an automatic signal which will indicate when the switch has beenelectrically operated; also certain structural features which arecapable of use in various types of switches other than the type hereindisclosed.

The various features of the invention will be best understood byreference to the following description taken in connection with theaccompanying drawing, and the scope of the invention will beparticularly pointed out in the appendedclaims.

In said drawing, Figure 1 is a side elevation of a double throw threephase oil switch constructed in accordance with my invention, partsbeing shown in section; Figs. 2 and 3 are diagrams illustratingdifferent positions of the switch operating mechanism; Fig. 4 is a planvlew and Fig. 5 1s a diagram of the switch circuits shown in connection.

mechanism of the switch are located at the rear of thehoard andsupported in part upon the frame and a slab 16 of insulating materiaicarried thereby. An oil can 17 is secured. to the under side of theframe 15 and surrounds the switch contacts which extend from the lowerside of the support 16. These contacts comprise in the present instancethree fixed' contacts 18 and three fixed contacts 19 arranged onopposite sides of three center contacts 20. The center contacts 20furnish a means of support for three movable Lshaped contacts 21. Theouter ends 21 a of the contacts 21 are adapted to engage thespring-pressed fingers 22 of the terminals 18, while the other ends 21are adapted to engage like spring-pressed fingers 23 on the contacts 19.The contacts 21 are rigidly connected together by a bar 21 andconstitute the movable element of the switch. The fixed contacts 18, 19and 20 extend tln'ough the slab 16 and are provided at their upper endswith suitable terminals 18, 19 and 20 respectively.

Movement is transmitted from the operating lever 11 on the front of theswitchboard 10 to the movable switch element by means of a collapsibleconnection composed of links 24 and 25 connected at their outer ends tothe lever and the bar 21 respectively, and at their inner ends to cranks26 27, pivoted to a suitable support on the frame 15. Coiled tensionsprings 28 connect the outer ends of the cranks 26 and 27 and tend todraw them together to collapse the connection between the lever and theswitch element. This connection may be locked. against collapse by thetoggle 29 extending between the same points as the springs 28 and.adapted to be slightly overset to hold the parts in position. It will beapparent that when thus locked the connection is made rigid and anymovement given to the 1 33 and securely locks the switch againstmovement. The switch cannot be moved from this position. until the pawlis withdrawn. This is accomplished by means of a pull or release rod 34which is secured at one end to the pawl 30 and extends through theswitchboard to its face where it terminates in a button 35. When thepawl 30.is allowed to act the shoulders 31 and 32 limit the throw of theswitch in a manner which will be more fully described hereinafter.

One of the links of the toggle 29 is provided with a T-shaped projection36 whose outer end. extends in the paths of movement of three armaturesdesignated 37, 38 and 39. These armatures are suitably pivoted uponsupports extending 'lroni the upper side of the slab 16, the ends of thearmatures 37 and 39 adjacent to the projection 36 are drawn downward bymeans of tension springs 40 provided with suitable adjusting screws 41and the corresponding end of the central armature 38 is provided with aweight 42 which performs a corresponding function. The opposite ends ofthe armatures are located directly above three trip magnets '43, 44 and45. The windings of the magnets 43 and 45 are connected each. in serieswith its adjacent switch contact 18 and between said contact and itsterminal 18. These connections are more clearly shown in Fig.

i 5, in which. 46, 47 and 48 designate the supply leads of a three-phasedistribution circuit in connection with which the switch hereinbeforedescribed is adapted to be used. These leads are connected to the fixedcontacts 18 of the switch by means of the connecting wires 49, 50 and51, the trip coils 43 and 45 being included in the wires 49 and 51. Inthis diagram 52 designates a threephase electric motor whose terminalsare connected to the switch contacts 20; and 53 designates a compensatorwhose coils are connected at intermediate points to the terminals 19 19of the switch. The compensator is connected in Y, the coils at one endbeing connected together and at the opposite ends being connected to theleads 46, 47 and 48. The trip magnet 44 is included in an independentcircuit including the manuallyoperated switch 45. For the purpose oi"indicating when the main switch is automatically tripped an auxiliaryswitch 46 together with a lamp 47 are also included in an independentcircuit. The switch 46 comprises a clip 46 mounted on a fixed supportand a plug 46 carried upon an arm 46 extending from one of the links ofthe looking toggle 29.

in the operation of the main switch, assuming that it has beenautomatically tripped. by energizing any one of the magnets 43, 44 and45, the parts will be in position illustrated in Fig. 2, that is, thetoggle 29 will be brokenthrough the agency of the actuating armature 37,or 39, as the case may be, and the connection between the lever 11 andthe movable switch element will be .collapsed, leaving the operatinglever 11 in itsclosed position, that is, in a position to be engaged bythe latch 12. With the parts in this position the pawl 30 will be seatedin the notch 33 and the switch held open. If now it is desired to startthemotor 52, the rod 34 is drawn out so as to release the pawl 30, andwhile thus drawn the operating lever 11. is freed from its latch 1.2 anddrawn outward into the position shown" in Fig. 3. The first portion ofthis movement of the operating lever straight-ens the toggle 29 andextends the springs 28 thus establishing a rigid connection between. thelever and the movable switch element and leaving the springs understrain. The latter portion of the movement throws the contacts 21 intoengagement with the fixed contacts 19 thus connecting the motor 52 tothe supply leads through the compensator This movement also leaves thepawl 30 in engagement with the shoulder 32 of the crank 27. After themotor has speeded up the switch is thrown into the running position bydrawing the operating lever 11 back to the position shown in Fig. 2.Since the connection between the operating lever and the movable elementof the switch is maintained rigid thrmighout this movement the contacts21 are thrown into engagement with the contacts 18 thus leaving themotor connected directly to the supply leads. In this movement thelocking pawl 30 is prevented. from dropping into the notch 33 by reasonof the length of the side 33 of the notch being greater than theopposing side thus permitting the pawl to pass clear of the notch underthe quick closing movement as will be apparent from the illustration inFig. 1. From this time on in case of an overload on either side of thesystem the magnet 43 or 45 Will be energized and the switchatuomatically tripped. in the manner hereinbefore described When theswitch is thus automatically tripped the breaking of the toggle 29forces the plug 46 of the switch 46 into engagelighted and serves toindicate the condition of the switch.

it is obvious that alterations and modifications may be made in thestructure herein disclosed without departing from the spirit and scopeoi my invention. l lJl'XGIGfOlG do not wish to be limited to thespecific matter disclosed bnt aim to cover by the terms of the appendedclaims all such alterations and modifications.

hat I claim as new and desire to secure by Letters Patent of the UnitedStates, is,

1. The combination with a switch having its open position between twoclosed posi tions and biased to open when closed, of means forautomatically tripping the switch to allow it to open, and means forantomatically locking the switch in open position when automaticallytripped.

2, The combination with a switch having an open position between twoclosed posi' tions and biased to open when closed, of means forautomatically tripping the switch to allow it to open, and means forstopping the switch in its open position when thrown from one of saidclosed positions and permitting it to pass freely through the openposition to said closed position when thrown from the other closedposition.

3. The combination with a switch having an open position between twoclosed positions and biased to open when closed, of mechanical means forstopping the switch in its open position whenever thrown from one closedposition and permitting it to pass freely through the open position tosaid' closed position when thrown from the other closed position.

-l. The combination of a switchboard, a double throw switch located atthe rear thereof, an operating lever therefor mounted on the face of theboard, means for locking the switch in its open position, and a releaserod therefor extending through the switch-' board.

5. An electric switch comprising a movable element, an operating lever,a collapsible connection between said lever and said movable element, aspring tending to collapse said connection, means for locking the partsagainst collapse, means operative to hold said element in its openposition, and means for rendering said holding means inoperative.

6. A double-throw electric switch compris ing a movable element havingits open position between its closed positions, an operating lever, acollapsible connection between said lever and said movable element, aspring tending to collapse said connection, means for locking the partsagainst collapse, and means operative when the connection is collapsedto hold. the switch element to allow the connection to be drawn out intonon-collapsed position by the movement ofthe lever to operate theswitch.

7. An electric switch comprising a movable eleinent, an operating lever,a collapsible connection between said lever and said movable element, aspring tending to collapse said connection, means for locking the partsagainst collapse, and a latch for holding 'said movable element when theswitch is open to allow the connection to be drawn out intonon-collapsed position by the movement of the lever to operate theswitch.

8. An electric switch comprising a movable element, an operating lever,pivoted links connected to said movable element and to said operatinglever and forming a collapsible connection between said lever and saidmovable element, a spring tending to collapse said connection, means forlocking its parts against collapse, and a latch engaging said connectionfor holding said movable element when the switch is open to allow theconnection to be drawn out into non-collapsed position by the movementof the lever to operate the switch.

9. An electric switch comprising a movable element, an operating lever,a crank pivoted at one end to the operating lever, a support for theother end of said crank, a crank pivoted at one end to the movablemember and mounted at the other end on said support, a collapsibleconnection between said cranks, means for locking the parts againstcollapse, and a latch for engaging one of said cranks to allow theconnection to be drawn out into non-collapsed position by the movementof the lever to operate the switch 10. An electric switch comprising amovable element, an operating lever, a crank pivoted at one end to theoperating lever, a support for the other end of said crank, a crankpivoted at one end to the movable member and mounted at the other end onsaid support, a collapsible connection between said. cranks, means forlocking the parts against collapse, a latch for engaging one of saidcranks to allow the connection to be drawn out into non-collapsedposition by the movement of the lever to operate the switch, and meansfor releasing said latch.

11. An electric switch, comprising a movable element, an operatinglever, a collapsible connection therebetween, a spring tending tocollapse said connection, means for locking the same against collapse,means for restraining the movement of the lever end of the connectionwhen the switch is in closed position, means for tripping the lockingmeans where by the connection is allowed to collapse and the switch isthereby opened and means for rendering said restraining me ansinoperative.

12. An electric switch, comprising a movable element, an operatinglever, a collapsible connection therebetween, a spring tending tocollapse said connection, means for locking means responsive topredetermined electrical conriitions 1n the circuit for tripping thelocking means, wherety the CODllGCilOIl is allowed to collapse and theswitch is thereby opened and means for rendering saiil restraining meansinoperative.

13. An electric switch, comprising operating means adaptezl to heplaceif. under strain and released to actuate the switch, releasingmeans therefor, means for automatically locking the switch againstmovement after being thus actuated, anrl an operating lever for settingthe operating mechanism while the switch remains locked and throwing theswitch when unlocked to another operative position.

14. A double throw electric switch, comprising a horizontal support,cooperating contacts on the under side thereof arranged to break in oil,an operating lever, and operating means located above said support andcomprising means for stopping the switch in its open position whenthrown from one closed position and permitting it to pass freely throughthe open. position to the said closed position when thrown from theother close-tiv position.

15. The combination with a switch having an open position between twoclosed. positions, ofa latch, and a cooperating notched surface arrangedto lock the switch in its open position when thrown from one closedposition and permitting it to pass freely through the open position tosaid ciosecl position when thrown from the other closed position.

16. The combination with a switch having an open position between twoclosetl positions, of a latch, and a cooperating surface comprising acentral notch having sides of unequal length wherety the latch willengage the notch to lock the switch in the open position when the switchis thrown in one clirection and. will ride freely over said notch topermit the switch to pass from one closed position to the other whenthrown in the opposite direction.

In witness whereof, I have hereunto set my hand this 28th (lay of July,1904.

EDWARD M. HEVVLE'IT.

Witnesses BENJAMIN B. HULL, HELEN ORFORD.

